Crossing the intestinal barrier

As inflammatory reactions can rapidly become fatal, it is therefore necessary to reduce the formation of activated oxygen species by acting on the enzymes that produce them. The problem that researchers are often confronted by is the fact that the different molecules which have been identified for their antioxidant properties, polyphenols principally, must cross the intestinal barrier in order to become active. In other words, it is not enough to give an antioxidant in order to have quickly an efficient effect. Part of the active ingredient is eliminated and does not cross the intestinal barrier. This is why fundamental research is essential in order to determine the best way of increasing the efficiency of the active ingredient. Similarly, it is not enough to eat passion fruits, even in great quantities, in order to benefit from its antioxidant properties. Firstly, because the active ingredient is not concentrated as it would be in a medicine and secondly, because the greatest part of the antioxidants is not absorbed by the organism. Likewise, it seems more and more likely that dietary supplements containing antioxidants, sold under the label of “neutraceutical food” are not as efficient as hoped for or expected. 


Thierry Franck, researcher at CORD and co-author of this study points out: “Nevertheless, it is beneficial to eat fruit and vegetables. It is micro doses that are absorbed and which have positive effects on health. Regular consumption of fruits which have antioxidant properties clearly has a protective effect, but it is not sufficient when the individual is confronted by an uncontrolled inflammatory reaction”. Among the fruits which are of interest due to their antioxidant properties, the researchers have studied the pulp of passion fruit (Passiflora edulis and Passiflora alata) as well as the peel of Passiflora  edulis.

Passion fruit: a source of antioxidants

The antioxidant activity of extracts from the pulp and skin of the passion fruit has been studied on the oxidant activity of neutrophils and myeloperoxidase (MPO) of neutrophils (defense enzyme producing powerful oxidants), two elements that play a key role in inflammation. The effects of extracts from the passion fruit on the production of oxidizing species by the stimulated neutrophils have been assessed by a method of  chemiluminescence (CL) and their effects on the activities of the purified myeloperoxidase were measured by the SIEFED method (Specific Immunological Extraction Followed by Enzymatic Detection). The extracts of peel from Passiflora edulis show the strongest antioxidant properties from the measures carried out, thus opening the way for future uses as a source of natural flavonoids (polyphenols).